Saturday, November 28, 2015

NTT DOCOMO announced results from several recent 5G trials, each of which surpassed the gigabit barrier. Some highlights:

A 5G trial it conducted with Nokia Networks at the Roppongi Hills high-rise complex in Tokyo on October 13 achieved data transmission in excess of 2Gbps. The trial used millimeter-wavelength signals with an extremely high frequency of 70GHz, a key development for the eventual commercial use of 5G wireless technology in actual-use environments. To date, no test had achieved a 5G data transmission in a commercial complex, such as a shopping mall, due to problems with base stations being out of line of sight and diffused reflections causing the attenuation of highly directional millimeter signals. This time, however, the trial was successful thanks to the use of two new technologies: beamforming, which focuses radio waves in a specific direction, and beam tracking to control beam direction according to the mobile device's location.

A 5G trial with Samsung Electronics in Suwon-city, South Korea on November 12 achieved a maximum data-receiving speed of more than 2.5Gbps. This was accomplished in a vehicle travelling with a speed of 60km/h. The trial used a 28GHz high-frequency signal in combination with beamforming with a high number of antenna elements and beam tracking.

A 5G trial with Ericsson verified the feasibility of massive multiple-input multiple-output (MIMO) technology by achieving a real-time data-receiving speed of more than 10Gbps using Ericsson 5G radio prototypes with a 15GHz frequency band on November 19.

A 5G trial with Fujitsu confirmed a multi-base-station cooperative transmission system by achieving a data-receiving speed of over 11Gbps in total of four mobile devices with a 4.6GHz signal on October 26.

A 5G outdoor data transmission trial conducted by DOCOMO, DOCOMO Beijing Communications Laboratories and Huawei Technologies on November 18 achieved a multi-user MIMO (MU-MIMO) transmission of 43.9bps/Hz/cell, which was 3.6-times more efficient than past outdoor trials of LTE-Advanced based MU-MIMO technology.